Pulmonary arterial capacitance in patients with heart failure and reactive pulmonary hypertension.

AIMS: Reactive pulmonary hypertension (PH) is a severe form of PH secondary to left-sided heart failure (HF). Given the structural and functional abnormalities in the pulmonary vasculature that occur in reactive PH, we hypothesized that pulmonary artery capacitance (PAC) may be profoundly affected, with implications for clinical outcome. METHODS AND RESULTS: We studied 393 HF patients of whom 124 (32%) were classified as having passive PH and 140 (36%) as having reactive PH, and 91 patients with pulmonary arterial hypertension (PAH). Mean PAC was highest in patients without PH (4.5 ± 2.1 mL/mmHg), followed by the passive PH group (2.8 ± 1.4 mL/mmHg) and was lowest in those with reactive PH (1.8 ± 0.7 mL/mmHg) (P = 0.0001). PAC and pulmonary vascular resistance (PVR) fitted well to a hyperbolic inverse relationship (PAC = 0.25/PVR, R(2) = 0.70), with reactive PH patients dispersed almost predominantly on the flat part of the curve where a reduction in PVR is associated with a small improvement in PAC. Elevated PCWP was associated with a significant lowering of PAC for any PVR (P = 0.036). During a median follow-up of 31 months, both reactive PH [hazard ratio (HR) 2.59, 95% confidence interval (CI) 1.14-4.46, P = 0.02] and reduced PAC (HR 0.72 per 1 mL/mmHg increase, 95% CI 0.59-0.88, P = 0.001) were independent predictors of mortality. CONCLUSIONS: The development of reactive PH is associated with a marked reduction in PAC. PAC is a strong independent haemodynamic marker of mortality in HF and may contribute to the increased mortality associated with reactive PH.

Influence of attenuation correction on transient left ventricular dilation in dual isotope myocardial perfusion imaging in patients with known or suspected coronary artery disease.

The aim of this study was to assess the effect of attenuation correction (AC) on left ventricular (LV) volumes and LV transient ischemic dilatation (TID) during dual-isotope single-photon emission computer tomographic (SPECT) myocardial perfusion imaging (MPI). Ninety-six patients (mean age 58 ± 11 years, 15% women, 38 patients completed exercise and 58 dipyridamole pharmacologic stress tests) assessed for known or suspected coronary artery disease underwent dual-isotope thallium-201 rest and technetium-99m sestamibi stress SPECT MPI with computed tomography-based AC. The TID ratio was calculated separately for non-AC and AC SPECT MPI studies as the ratio of the LV endocardial volume at stress divided by LV endocardial volume at rest. The mean and range of the gated LV ejection fraction during exercise and pharmacologic stress was 54 ± 12% (29% to 80%) and 58 ± 12% (27% to 80%), respectively. In the exercise stress group, the same mean LV endocardial volumes in non-AC and AC stress (76.4 ± 30 and 76.5 ± 28) and rest (66.3 ± 26 and 66.4 ± 24) studies were found (p = 0.90). There was no statistical difference between the mean exercise TID ratio in non-AC and AC studies (1.27 vs 1.31, respectively, p = 0.10). The same mean LV endocardial volumes in non-AC and AC in pharmacologic stress (79.9 ± 42 and 80 ± 41) and rest (71.4 ± 41 and 72.3 ± 37), respectively, were found (p = 0.50). There was no statistical difference between the mean dipyridamole TID ratio in non-AC and AC studies (1.20 vs 1.17, respectively, p = 0.10). In conclusion, LV volumes and TID indexes obtained on SPECT MPI with exercise or pharmacologic stress using dipyridamole are not affected by AC.

Patient safety and outcomes from live case demonstrations of interventional cardiology procedures.

OBJECTIVES: The goal of this study was to examine the safety and results of interventional procedures performed during the broadcast of live case demonstrations. BACKGROUND: Professional meetings using live case demonstrations to present cutting-edge technology are considered a valuable educational resource. There is an ongoing discussion on whether patients who are treated during live case demonstrations are exposed to a higher risk. METHODS: Between 1998 and 2010, 101 patients were treated during live transmissions from a single center in 15 invasive-cardiology conferences. Technical success was defined as the ability to effectively perform the planned procedure without any major complication. The primary endpoint of the study was the composite occurrence of death, myocardial infarction, or stroke. RESULTS: The interventional procedures included coronary (n=66), carotid (n=15), peripheral (n=1), valvular (n=2), congenital heart disease (n=12), and complex electrophysiological mapping and ablation interventions (n=7). In 4 cases, the intended procedure was not done. The procedure was technically successful in 95%. In 5 cases, the procedure was unsuccessful because of the inability to cross a chronic total occlusion. There were no deaths during the hospital stay, and the composite primary endpoint occurred in 2 patients: a minor stroke following an atrial fibrillation ablation and a rise in serum troponin levels after percutaneous coronary intervention. These results were no different from those of 66 matched controls who underwent procedures performed by the same operators but not as live case demonstrations (relative risk: 0.32; 95% confidence interval: 0.02 to 3.62, p=0.62). CONCLUSIONS: In this consecutive series of interventional cardiology procedures that were performed by expert operators during live demonstration courses, the procedural and 30-day clinical outcomes were similar to those found in daily practice and to those that have been reported in the contemporary published data. These results suggest that broadcasting live case demonstrations in selected patients from selected centers may be safe.

Multidetector computed tomography predictors of late ventricular remodeling and function after acute myocardial infarction.

BACKGROUND: Despite advent of rapid arterial revascularization as 1st line treatment for acute myocardial infarction (AMI), incomplete restoral of flow at the microvascular level remains a problem and is associated with adverse prognosis, including pathological ventricular remodeling. We aimed to study the association between multidetector row computed tomography (MDCT) perfusion defects and ventricular remodeling post-AMI. METHODS: In a prospective study, 20 patients with ST-elevation AMI, treated by primary angioplasty, underwent arterial and late phase MDCT as well as radionuclide scans to study presence, size and severity of myocardial perfusion defects. Contrast echocardiography was performed at baseline and at 4 months follow-up to evaluate changes in myocardial function and remodeling. RESULTS: Early defects (ED), late defects (LD) and late enhancement (LE) were detected in 15, 7 and 16 patients, respectively and radionuclide defects in 15 patients. The ED area (r=0.74), and LD area (r=0.72), and to a lesser extent LE area (r=0.62) correlated moderately well with SPECT summed rest score. By univariate analysis, follow-up end-systolic volume index and ejection fraction were both significantly related to ED and LD size and severity, but not to LE size or severity. By multivariate analysis, end-systolic volume index was best predicted by LD area (p<0.05) and ejection fraction by LD enhancement ratio. CONCLUSIONS: LD size and severity on MDCT are most closely associated with pathological ventricular remodeling after AMI and may thus play a role in early identification and treatment of this condition.

Integrated SPECT/CT for assessment of haemodynamically significant coronary artery lesions in patients with acute coronary syndrome.

PURPOSE: Early risk stratification in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) is important since the benefit from more aggressive and costly treatment strategies is proportional to the risk of adverse clinical events. In the present study we assessed whether hybrid single photon emission computed tomography (SPECT)/coronary computed tomography angiography (CCTA) technology could be an appropriate tool in stratifying patients with NSTE-ACS. METHODS: SPECT/CCTA was performed in 90 consecutive patients with NSTE-ACS. The Thrombolysis in Myocardial Infarction risk score (TIMI-RS) was used to classify patients as low- or high-risk. Imaging was performed using SPECT/CCTA to identify haemodynamically significant lesions defined as >50% stenosis on CCTA with a reversible perfusion defect on SPECT in the corresponding territory. RESULTS: CCTA demonstrated at least one lesion with >50% stenosis in 35 of 40 high-risk patients (87%) as compared to 14 of 50 low-risk patients (35%; TIMI-RS<3; p<.0001). Of the 40 high-risk and 50 (16%) low-risk TIMI-RS patients, 16 (40%) and 8 (16%), respectively, had haemodynamically significant lesions (p=0.01). Patients defined as high-risk by a high TIMI-RS, a positive CCTA scan or both (n=45) resulted in a sensitivity of 95%, specificity of 49%, PPV of 35% and NPV of 97% for having haemodynamically significant coronary lesions. Those with normal perfusion were spared revascularization procedures, regardless of their TIMI-RS. CONCLUSION: Noninvasive assessment of coronary artery disease by SPECT/CCTA may play an important role in risk stratification of patients with NSTE-ACS by better identifying the subgroup requiring intervention.

Hybrid cardiac SPECT/64-slice CTA-derived LV function parameters: correlation and reproducibility assessment.

UNLABELLED: The purpose of this study is to define the relationship between SPECT and CTA measured parameters of left ventricular (LV) function and volumes obtained in a single session using SPECT/64-slice CT hybrid imaging device, and in addition, to assess the reproducibility of LV parameters measured using 64-slice CTA. MATERIALS AND METHODS: Seventy-six patients with suspected or known coronary artery disease underwent cardiac CTA and GSPECT in one session using a hybrid SPECT/CT device. LV end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were measured on each component of the hybrid device. For the CTA component, these parameters were re-measured by the same investigator and by a second investigator with an interval of 3-54 weeks. Corresponding GSPECT and CTA measured parameters were compared. For CTA, intra-observer and inter-observer variability of LV function and volume measurements were calculated. RESULTS: A very good correlation was found between the GSPECT and CTA measured LVEF (r=0.81), ESV (r=0.90) and EDV (r=0.82). There was a small positive difference by CTA measured LVEF (3.9+/-14.2%), and more prominent positive differences by CTA measured ESV and EDV (9.8+/-14.8 and 44.9+/-23.1cm(3), respectively). There was excellent reproducibility in the measurements of all parameters with very low intra- and inter-observer variability (r=0.93 for EF and 0.98 for EDV and ESV). CONCLUSIONS: Although a good correlation was found between the EF measurements obtained from CTA and SPECT, interchangeable use of EF measurements between the two modalities should be done cautiously and interchangeable use of LV EDV and ESV should be avoided.

Novel solid-state-detector dedicated cardiac camera for fast myocardial perfusion imaging: multicenter comparison with standard dual detector cameras.

OBJECTIVE: To compare the diagnostic performance of a new dedicated ultrafast solid-state cardiac camera (Discovery NM 530c [DNM]) with standard dual detector cameras (S-SPECT) in myocardial perfusion imaging. The primary goal was a per-patient analysis of diagnostic performance of the DNM using S-SPECT as the reference standard. METHODS AND RESULTS: In total, 168 patients underwent one-day Tc-99m tetrofosmin rest/stress myocardial perfusion SPECT. DNM and S-SPECT images were obtained with the same injected doses. The DNM camera uses an array of cadmium zinc telluride pixilated detectors and a multipinhole collimator simultaneously imaging all cardiac views with no moving parts. Rest and stress acquisition times were 4 and 2 minutes for DNM and 14 and 12 minutes for S-SPECT. Two blinded readers independently interpreted all scans on a patient level and on a vascular territory level using a standard five-point scale. Interobserver differences were resolved by a third observer. Agreement between DNM and S-SPECT for presence or absence of myocardial perfusion defects on a per-patient analysis was 91.9% and 92.5%, respectively. Correlation coefficients of rest and stress left ventricular ejection fractions were 0.87 (P < .01) and 0.90 (P < .01). CONCLUSION: The diagnostic performance of DNM is comparable to that of S-SPECT on a per-patient basis. However, superior image quality can be achieved with significantly shorter acquisition times with DNM because of improved count sensitivity and image contrast over S-SPECT.

Cardiology consultation as a gatekeeper prior to cardiac multi-detector computed tomography scan.

BACKGROUND: Multi-detector computed tomography has advanced enormously and now enables non-invasive evaluation of coronary arteries as well as cardiac anatomy, function and perfusion. However, the role of cardiac MDCT is not yet determined in the medical community and, consequently, many clinically unnecessary scans are performed solely on a self-referral basis. OBJECTIVES: To prospectively evaluate the role of a cardiologist consultation and recommendation prior to the scan, and the influence on the diagnostic yield of cardiac MDCT. METHODS: In our center a CT service was initiated, but with the prerequisite approval of a cardiologist before performance of the CT. Each individual who wanted and was willing to pay for a cardiac CT was interviewed by an experienced cardiologist who determined whether cardiac MDCT was the most appropriate next test in the cardiovascular evaluation. Subjects were classified into three groups: a) those with a normal or no prior stress test, no typical symptoms and no significant risk factors of coronary artery disease were recommended to perform a stress test or to remain under close clinical follow-up without MDCT; b) those with an equivocal stress test, atypical symptoms and/or significant risk factors were allowed to have cardiac MDCT; and c) those with positive stress test or clinically highly suspected CAD were advised to go directly to invasive coronary angiography. CT findings were categorized as normal CAD (normal calcium score and no narrowings), < 50% and > 50% CAD. RESULTS: A total of 254 people were interviewed, and in only 39 cases did the cardiologist approve the CT. However, 61 of the 215, despite our recommendation not to undergo CT, decided to have the scan. Assessment of the 100 cases that underwent MDCT showed a statistically significant better discrimination of significant CAD, according to the cardiologist's recommendation: MDCT not recommended in 3/54 (6%) vs. MDCT recommended in 12/39 (31%) vs. recommended invasive coronary angiography in 4/7 (57%)(P<0.001). CONCLUSIONS: Detection of coronary calcification, as well as MDCT angiography can provide clinically useful information if applied to suitable patient groups. It is foreseeable that MDCT angiography will become part of the routine workup in some subsets of patients with suspected CAD. Selection of patients undergoing MDCT scans by a cardiologist improves the ability of the test to stratify patients, preventing unnecessary scans in both high and low risk patients.

Dilated cardiomyopathy: an unusual complication of clozapine therapy.

BACKGROUND: A 42-year-old obese man presented with acute pulmonary edema. He had a history of chronic residual schizophrenia for which he had been taking clozapine for 7 years, but had no known prior cardiac disease. Echocardiography demonstrated severe biventricular systolic and diastolic dysfunction with severe left ventricular enlargement. Cardiac catheterization showed no coronary artery disease. INVESTIGATIONS: Physical examination, chest radiography, electrocardiography, transthoracic echocardiography, laboratory testing, viral serology, cardiac catheterization, coronary angiography and abdominal and renal ultrasonography. DIAGNOSIS: Clozapine-induced dilated cardiomyopathy. MANAGEMENT: Intravenous nesiritide, furosemide and morphine followed by oral heart-failure therapy comprising ramipril, metoprolol succinate, spironolactone, and furosemide. Clozapine therapy was withdrawn.

Angiographically uncertain left main coronary artery narrowings: correlation with multidetector computed tomography and intravascular ultrasound.

BACKGROUND: Angiographic assessment of left main coronary artery (LMCA) stenosis is often difficult and unreliable. To date, intravascular ultrasound (IVUS) is used to determine the significance of lesions in patients with LMCA stenosis of uncertain significance. We aimed to prospectively show the ability of multidetector computed tomography (MDCT) to assess LMCA luminal and plaque dimensions, and to characterize atherosclerotic plaque, as compared to IVUS and quantitative coronary angiography (QCA), in patients with angiographically uncertain LMCA stenosis. METHODS: Twenty patients, with angiographically uncertain LMCA stenosis, underwent coronary evaluation with IVUS, QCA and 16-slice MDCT. Minimal lumen diameter (MLD), minimal lumen area (MLA), lumen area stenosis (LAS) and plaque burden (PB) were assessed. RESULTS: The MLD (median [interquartile range]) was 3.2 mm (2.5-3.7) by IVUS, 2.8 mm (2.3-3.3) by QCA (r=0.52, P<0.05), and 2.8 mm (2.5-3.8) by MDCT (r=0.77, P<0.01). MDCT estimated MLA as 10.7 mm(2) (7.1-12.6) Vs. 9.9 mm(2) (6.5-13.5) by IVUS (r=0.93, P<0.01). Very high correlations were observed between MDCT and IVUS in assessing LAS (mean +/- SD) (25.8+/-19.1% and 29.0+/-24.9% respectively, r=0.83, P<0.01), and PB (49.2+/-15.8% and 49.2+/-19.7% respectively, r=0.94, P<0.01). MDCT assigned plaque as being non-calcified with a sensitivity of 100%, while calcified plaques with a sensitivity of 75%. CONCLUSION: A high degree of correlation was found between MDCT and IVUS regarding the assessment of minimal lumen diameter and area, lumen area stenosis and plaque burden as well as plaque characterization in patients with angiographically borderline LMCA stenosis. Therefore, in patients selected for non-invasive coronary tree evaluation, MDCT may provide a valuable tool for the assessment, decision-making and follow-up of patients with uncertain LMCA disease.

Diagnostic accuracy of myocardial hypoenhancement on multidetector computed tomography in identifying myocardial infarction in patients admitted with acute chest pain syndrome.

OBJECTIVE: To evaluate prevalence and diagnostic accuracy of myocardial hypoenhancement (MH) using multidetector computed tomography (MDCT) in patients admitted for acute chest pain syndromes. METHODS: Sixty-nine patients underwent first-pass MDCT, coronary angiography, and echocardiography. Using a standardized analysis protocol, left ventricular short-axis reformations were evaluated for presence, size, and density of MH in 16 myocardial segments. These were correlated with the presence and location of myocardial infarction (MI), regional myocardial dysfunction, and coronary artery disease. RESULTS: Myocardial hypoenhancement was found in acute MI (27/35), healed MI (6/14), unstable angina (3/9), and atypical chest pain (0/11). Sensitivity, specificity, and positive and negative predictive values of MH for diagnosing any MI were 67%, 85%, 92% and 52%, respectively. CONCLUSIONS: The presence of MH on MDCT in acute chest pain patients has high positive predictive value and specificity but only moderate sensitivity for presence of acute or healed MI using the strict criteria proposed in this study.

Is functional improvement after myocardial infarction predicted with myocardial enhancement patterns at multidetector CT?

PURPOSE: To prospectively evaluate the sensitivity of myocardial early perfusion defects (EDs) and late enhancement (LE) at multidetector computed tomography (CT) following acute myocardial infarction (AMI) to predict segment myocardial dysfunction and myocardial functional recovery (MFR), by using echocardiography as the reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Twenty-six patients (25 men, one woman; mean age, 53 years+/-9 [standard deviation]), underwent baseline multidetector CT, coronary angiography, and echocardiography within a week of AMI and a follow-up echocardiography at 3 months. ED, LE, and late hypoattenuation were compared with regional left ventricular function and MFR. A logistic regression model and generalized estimating equation analysis were applied to estimate the predictive effect of ED and LE. Differences between groups were evaluated by using nonpaired Student t tests. RESULTS: All EDs and LE corresponded with AMI location determined by using angiography and echocardiography. For occluded arteries (n=5), no relationship was found between the presence of ED or LE and MFR. For patent arteries (n=21), presence of LE had a respective sensitivity and specificity of 73% and 85% for predicting follow-up segment dysfunction, compared with 57% and 90% for ED. In abnormal baseline segments, nonrecovery was clearly related to the presence and size of segment defect area for both ED (odds ratio: 1.95 [95% confidence interval: 0.9, 4.1] per square centimeter) and LE (odds ratio: 1.85 [95% confidence interval: 1.2, 2.9] per square centimeter). Segments that recovered had significantly lower prevalence of ED and LE, and if present, were significantly smaller than in segments remaining abnormal (P<.05). CONCLUSION: The presence and size of ED and LE at multidetector CT is closely related to follow-up segment myocardial dysfunction and MFR.

Integrated single-photon emission computed tomography and computed tomography coronary angiography for the assessment of hemodynamically significant coronary artery lesions.

OBJECTIVES: The purpose of this study was to assess the physiologic significance of coronary artery lesions with an integrated single-photon emission computed tomography (SPECT) and computed tomography coronary angiography (CTCA) device. BACKGROUND: Myocardial perfusion imaging (MPI) with SPECT is of value for assessing the physiologic significance of coronary lesions. Computed tomography coronary angiography is a new technique to noninvasively detect coronary stenosis, with high sensitivity and negative predictive value (NPV) but lower specificity and positive predictive value (PPV). The experimental SPECT/CTCA hybrid imaging device (Infinia gamma camera and LightSpeed16 CT, General Electric, Milwaukee, Wisconsin) enables concurrent assessment of coronary anatomy and myocardial perfusion. METHODS: Fifty-six patients with angina pectoris underwent single-session SPECT-MPI and CTCA with the hybrid device and coronary angiography (CA) within 4 weeks. The ability of fused SPECT/CTCA images to diagnose physiologically significant lesions showing >50% stenosis and reversible perfusion defects in the same territory was determined and compared with CTCA stand-alone. RESULTS: Of a total of 224 coronary segments in 56 patients, 12 patients and 54 segments (23%) were excluded from further analysis of CTCA. Overall, 170 coronary segments were evaluated. The sensitivity, specificity, PPV, and NPV of CTCA were 96%, 63%, 31%, and 99%, respectively, as compared with 96%, 95%, 77%, and 99%, respectively, for SPECT/CTCA. CONCLUSIONS: Hybrid SPECT/CTCA imaging results in improved specificity and PPV to detect hemodynamically significant coronary lesions in patients with chest pain. Single-photon emission computed tomography/CTCA might play a potentially important role in the noninvasive diagnosis of coronary artery disease and introduce an objective decision-making tool for assessing the need for interventions in each occluded vessel.

PET/CT quantitation of the effect of patient-related factors on cardiac 18F-FDG uptake.

UNLABELLED: The effect of multiple patient-related factors on the degree of cardiac 18F-FDG uptake was assessed. METHODS: Five hundred four consecutive patients undergoing routine 18F-FDG PET/CT studies completed a clinical questionnaire. 18F-FDG uptake was measured as the mean standardized uptake value within the heart delineated on the CT component of the study. Univariate and multivariate analyses assessed the influence of 51 clinical factors on cardiac 18F-FDG uptake. RESULTS: On both multivariate and univariate analyses, cardiac 18F-FDG uptake was significantly lower in diabetics and in patients receiving bezafibrate or levothyroxine. Cardiac 18F-FDG uptake was significantly higher in men, patients younger than 30 y old, fasting duration of <5 h, patients with heart failure, and those receiving benzodiazepines. CONCLUSION: Cardiac 18F-FDG uptake was lower in patients receiving bezafibrate and levothyroxine and higher in patients receiving benzodiazepines. If further confirmed by prospectively designed studies, manipulation of these drugs may represent tools for optimized PET/CT imaging.

Contrast enhanced multi-detector computed tomography coronary angiography versus conventional invasive quantitative coronary angiography in acute coronary syndrome patients-correlation and bias.

BACKGROUND: Previous studies that compared multi-detector computed tomography (MDCT) non-invasive coronary angiography with conventional coronary angiography, did not assessed the ability of MDCT to detect stenotic lesions correctly in acute coronary syndromes (ACS) patients. The aim of the present study was to assess prospectively the correlation and bias between 16-slice MDCT coronary angiography and quantitative coronary angiography analysis (QCA) in these patients. METHODS: Patients underwent electrocardiogram-gated, 16-slice MDCT coronary angiography and routine invasive percutaneous coronary angiography with quantitative coronary angiography (QCA) analysis blinded to MDCT results. The correlation and the bias between the results of MDCT and QCA were assessed in segments observed by both modalities in vessels > or = 2 mm in diameter. RESULTS: 59 patients (81% male, age 56 +/- 11 years), admitted due to ACS, underwent MDCT and invasive coronary angiography. 544 segments were analyzed. The correlations between MDCT and QCA observed for the left anterior descending coronary artery (LAD), the left circumflex coronary artery (Cx), the right coronary artery (RCA) and for all analyzed segments were 0.74 (P < 0.0001), 0.54 (P < 0.009), 0.72 (P < 0.0001) and 0.70 (P < 0.0001), respectively. By Bland-Altman analysis, a small overestimation of the lesion severity with MDCT of 4.8% for the LAD, 5.9% for the Cx, and 3.3% for the RCA was observed. CONCLUSIONS: In ACS patients, MDCT contrast-enhanced coronary angiography provides good quantification of the luminal diameter as compared to coronary angiography, and it is characterized by a small overestimation bias.

Should primary percutaneous coronary intervention be the preferred method of reperfusion therapy for patients with renal failure and ST-elevation acute myocardial infarction?

Data from patients who had ST-elevation acute myocardial infarction and renal failure and were enrolled in the 2002 Acute Coronary Syndrome Israeli Survey (ACSIS) were studied to determine the effect of different myocardial reperfusion modalities on short- and long-term outcomes. Thirty-day crude mortalities were 8.3% in the thrombolysis group, 40.0% in the primary percutaneous coronary intervention group, and 29.7% in the no-reperfusion group (p = 0.03). Crude and adjusted mortality odds ratios that were observed at 7, 30, and 365 days, with the thrombolysis group as the reference, were 3.1 to 8.1 in the percutaneous coronary intervention group and 1.5 to 4.6 in the no-reperfusion group. Our results suggest that thrombolysis may represent the preferred modality of reperfusion therapy in patients with renal failure and ST-elevation acute myocardial infarction. A large randomized prospective study is needed to confirm these results.

Automatic determination of minimal cardiac motion phases for computed tomography imaging: initial experience.

Low motion phases for cardiac computed tomography reconstructions are currently detected manually in a user-dependent selection process which is often time consuming and suboptimal. The concept of motion maps was recently introduced to achieve automatic phase selection. This pilot study compared the accuracy of motion-map phase selection to that with manual iterative selection. The study included 20 patients, consisting of one group with low and one with high heart rate. The technique automatically derives a motion strength function between multiple low-resolution reconstructions through the cardiac cycle, with periods of lowest difference between neighboring phases indicating minimal cardiac motion. A high level of agreement was found for phase selection achieved with the motion map approach compared with the manual iterative selection process. The motion maps allowed automated quiescent phase detection of the cardiac cycle in 85% of cases, with best results at low heart rates and for the left coronary artery. They can also provide additional information such as the presence of breathing artifacts. Motion maps show promise as a rapid off-line tool to automatically detect quiescent cardiac phases in a variety of patients.

16-MDCT coronary angiography versus invasive coronary angiography in acute chest pain syndrome: a blinded prospective study.

OBJECTIVE: The purpose of our study was to prospectively evaluate the usefulness of CT coronary angiography versus invasive coronary angiography for the detection of clinically significant coronary artery disease in patients hospitalized for acute chest pain syndrome. SUBJECTS AND METHODS: Sixty-six consecutive patients (52 men and 14 women; average age, 57 +/- 11 [SD] years) who were hospitalized for acute chest pain syndrome underwent CT coronary angiography and invasive coronary angiography within an average time interval of 4 days. ECG-gated CT coronary angiography was performed with a 16-MDCT scanner (0.42-sec rotation time, 16 x 0.75 mm detector collimation). Beta-blockers were not administered routinely, and thus the average heart rate was 71 +/- 11 beats per minute. CT coronary angiographic images were evaluated concurrently by two radiologists, who were blinded to invasive coronary angiography results, for stenoses having a diameter of 50% or more, using a 15-segment classification, including all segments 2 mm or more in diameter. The consensus interpretation was compared with results of invasive coronary angiography. RESULTS: CT coronary angiography was technically successful in 59 patients (89%). After exclusion of 20 (3.1%) of 649 coronary segments, which were classified as nonevaluable by CT coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT coronary angiography for identifying significant coronary artery disease in the remaining 629 coronary segments were 80% (68/85), 89% (482/544), 52% (68/130), 97% (482/499), and 87% (550/629), respectively. The overall accuracy for the main vessels (left main, left anterior descending, left circumflex, and right coronary arteries) was 93%, 88%, 86%, and 86%, respectively. CONCLUSION: CT coronary angiography using a 16-MDCT scanner enables accurate noninvasive detection of significant coronary artery disease in patients hospitalized for acute chest pain syndrome. Furthermore, relative high sensitivity and specificity of CT coronary angiography can be achieved without pharmacologic manipulation of patient heart rates.